参考文章:https://www.liaoxuefeng.com/wiki/0014316089557264a6b348958f449949df42a6d3a2e542c000/001431927781401bb47ccf187b24c3b955157bb12c5882d000
进程间肯定是需要相互通信的。而进程间的通信方式有三种:
- 共享存储
- 消息传递
- 管道通信
Python的multiprocessing模块包装了底层的机制,提供了Queue、Pipes等多种方式来交换数据
以共享存储方式的对同一个队列进行输入输出以完成通信为例:
在父进程中创建两个子进程,一个往Queue写入数据,一个从Queue读出数据
# -*- coding:utf-8 -*-
from multiprocessing import Process, Queue
import os, time
# import random
# 写数据进程执行代码
def write(q):
print ("Process %s to write:" % os.getpid())
for value in [1, 2, 3, 4]:
print ("put value %d to queue" % value)
q.put(value)
# time.sleep(random.random())
time.sleep(1)
# 读数据进程执行代码
def read(q):
print ("Process %s to read" % os.getpid())
while True:
value = q.get()
print ("Get %d from queue" % value)
if __name__ == "__main__":
# 父进程中创建Queue,并传给各个子进程
q = Queue()
pw = Process(target=write, args=(q, ))
pr = Process(target=read, args=(q, ))
# 启动子进程
pw.start()
pr.start()
pw.join()
# 此处不可调用pr.join(),因为read是是循环,只能强行终止
# pr.join()
pr.terminate()
运行结果:
Process 5125 to write:
put value 1 to queue
Process 5126 to read
Get 1 from queue
put value 2 to queue
Get 2 from queue
put value 3 to queue
Get 3 from queue
put value 4 to queue
Get 4 from queue
Process finished with exit code 0